Fiat Seicento 1108 MPi please explain thanks

[Diwiak]

Hi guys,

I have lambda related troubles with my car(P0130, P0139(low signal),after approx. 100km it light-up again),
trying to solve them(cheap ELM327+MES) but dont understand some items, ifu could explain to me(cant find them in google, these forums or MES help file).


odometer- it shows higher value than I have on dashboard (97000 vs 90000km on dash)
odometer at last programming- 0
number of rewrites- 1

lambda1 signal precat- 0.1 - 0.9 V(approx)
lambda1 signal aftercat- 0 - 0.9 V(approx)

lambda1 diagnosis precat - swapping rich\lean
lambda1 diagnosis aftercat - lean\bottom limit

lambda1 status precat- closed loop
lambda1 status aftercat - closed\open swapping

lambda1 check- OK


-all these measured when hot (89-95C), ocasionally reving engine, how could I find whats wrong,
can u explain these values to me??
anyway car is running fine, reasonable mpg

appreciate your help

[alfa156sarajevo]

If you have "lambda" errors in your engine ecu and in parameters everything seams fine than it is probably problem with lambda.
To fix it you need to replace lambda. You can buy original from main dealer or you can by universal lambda which fits many other cars...

[Diwiak]

I replaced one lambda, and received P0136 again (high signal, when cold at engine start..).

What means "below cat"?? which lambda is it??


one more thing, is "self adaptation reset" and "phonic wheel learn reset" worth it???

[alfa156sarajevo]

Different cars have different number of lambda sondas.
Older ones have usually one lambda sonda before catalyst (or CAT how it is written sometimes) and newer cars have 2 lambda before catalyst and 1 or 2 after catalyst. Number of lambda sonda after catalyst depends of size of engine and on bigger engines you can find 2 lambda sonda but on smaller engines you will find only one lambda sonda.

Yes you can do "self adaptation reset" and maybe it will help you but "phonic wheel learn reset" will not help you when changing lambda sonda…

[Diwiak]

Yes you can do "self adaptation reset" and maybe it will help you but "phonic wheel learn reset" will not help you when changing lambda sonda…

..can u explain what are these two items making..??..

[alfa156sarajevo]

First one does reset parameters in engine ECU.
Second one does reset of small wheel which is located in air intake pipe.

[tzok]

First one does reset parameters in engine ECU.
Second one does reset of small wheel which is located in air intake pipe.

No - phonic wheel adaptation is the crankshaft position sensor adaptation (also known as an rpm sensor), or camshaft to crankshaft phonic wheels (rpm to phase) signal synchronization. Phonic wheel itself is a very general term - it is usually a wheel with magnetic "tooths" which are read by an inductive or a Haal-effect sensor. It is a variant of an encoder wheel/rotary encoder (which can work also with an optical sensor, like in old computer "ball" type mice). You also have phonic wheels working with the ABS sensors.

Pre-cat (or above cat) lambda is the the main sensor (control), post-cat (or below cat) lambda is a supplementary sensor (diagnostic). You may verify the main sensor by comparing the lambda read outs from ECU (via MES) with lambda read outs from exhaust gas analyzer at workshop or diagnostic station. Lambda errors can be caused by poor condition of engine - low compression, faulty temperature sensors, damaged injectors or spark plugs/ignition cables/coils and everything what leads to misfires or mixture (AFR) deregulation.

[Diwiak]

hi guys,

there was one lambda gone (MES was showing values around 5V), so swap it with new one, also I did full service with timing belt and tensioner, spark plugs and leads, than did selfadaptation reset and phonic wheel reset too.

one thing I noticed was intake air temeperature showing around 33C degrees, and when engine was hot it shows around 50C - is that allright (outside temps here are around 25C now)??

now running fine, will let you know if something will be wrong again. Thanks.

[tzok]

one thing I noticed was intake air temeperature showing around 33C degrees, and when engine was hot it shows around 50C - is that allright (outside temps here are around 25C now)??

That's absolutely correct. IAT will be equal to the ambient temperature only after a night (at least 5-6 h without running engine), before starting the engine.

[alfa156sarajevo]

@ tzok
Yes, you are right! Thanks for explaining everything in details for all of us.
I did not have time to explain myself but in general this function "Phonic wheel adaptation" is done when on dashboard rpm are jumping by themselves. RPMs are going up and down when car is standing (parked) and engine running (like when you are standing in front of traffic light).

It is good to do the cleaning of air intake pipe with some spray for carburettors or with WD40 spray.
After everything is cleaned in air intake pipe including the small wheel than execute function "Phonic wheel adaptation".
Press the throttle 3 times up tu 4500-5000 rpm as it is described in yellow window and that is it. Car is ready to go.
In most of cases this thing is helpful…